systems theory vs bailiwick

systems theory and bailiwick both are nouns.

Word	Noun	Adjective	Verb	Adverb
systems theory	Yes	No	No	No
bailiwick	Yes	No	No	No

As nouns, bailiwick is a hypernym of systems theory; that is, bailiwick is a word with a broader meaning than systems theory:

systems theory: the interdisciplinary study of systems in general, with the goal of elucidating principles that can be applied to all types of systems at all nesting levels in all fields of research.
bailiwick: a branch of knowledge

Other hypernyms of systems theory include discipline, field, field of study, study, subject, subject area, subject field.

systems theory (noun)	bailiwick (noun)
the interdisciplinary study of systems in general, with the goal of elucidating principles that can be applied to all types of systems at all nesting levels in all fields of research.	a branch of knowledge
	the area over which a bailiff has jurisdiction